Electro-magnetic instrument



" (No Model.)

P. B. DELANY. ELEGTRO MAGNETIC INSTRUMENT.

No. 426,247. Patented Apr. 22, 1890.

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UNITED STATES PATENT OFFICE.

PATRICK B. DELANY, OF SOUTH ORANGE, NEIV JERSEY.

ELECTRO-MAGNET IC INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 426,247, dated April 22, 1890.

Application filed January 30, 1890. Serial No. 338,564. (No model.) i

To whom it may concern..-

Be it known that I, PATRICK B. DELANY, a citizen of the United States, residing at South Orange, State of New Jersey, have invented certain new and useful Improvements in Electro-Magnetic Instruments, of which the following is a specification.

The invention is applicable to all such instruments in which an armature having a re tractable or biasing spring is attracted by a magnet; but the invention is more especially designed for use with telegraphic relays. The telegraph-operator must frequently adjust the spring of his relay armature-lever to compensate for varying conditions of the battery or circuit, and in adjusting the spring to increase its tension he is liable, through carelessness, to overstrain the spring, and even to wind it upon the rotating pin or post by which it is adjusted.

My invention is designed to prevent the posibility of such accidents, which impair the efficiency of the springs and frequently render them useless.

Another feature of my invention comprehends the idea of preventing the total relaxation of the spring-that is, providing for the minimum tension below which the spring cannot be adjusted. In either case when the limit of adjustment by the manipulation of the spring has been reached further adjustment must be effected by the adjustment of the electro-magnet itself.

In the accompanying drawings, Figure l is a side elevation; Fig. 2, an end view of a tie vice for limiting the adjustment of the spring, and Figs. 3 and at are detail views of modified ways of limiting the adjustments of the spring.

A represents an ordinary adjustable electro-magnet; B,its armature; O, the retraetile spring of the armature; D, the cord leading from the end of the armature-spring to the rotating post E, having a thumb-wheel e and mounted in the sliding or adjustable arm F supported in a post Gr. This is the ordinary construction, and is well known.

The cord D passes through a guide Y, preferably having an elongated vertical opening for the passage of the cord. The overstraining of the spring is prevented by providing the cord with a device that will abut against the guide Y and prevent further movement of the cord through it. A simple and 0011- venient wayof effecting this is to form aknot (Z in the cord between the end of the spring and the guide Y. As this knot cannot pass through the opening in the guide Y the operator cannot strain the spring beyond the point where the knot strikes the guide. It is therefore impossible toinjure the spring, and of course it is never possible in a thoughtless moment to wind the spring upon the rotating post E. \Yhen the limit of adjustment has been reached, a further adjustment may be effected in the ordinary way by the adjustment of the magnet away from the armature.

In Fig. 3 I have shown another manner of accomplishing the desired result. In this case the cord c, need not pass through a guide Y, the limitation of the adjustment of the spring being effected in the following manner: A light cord 0, passing centrally through the spring, is connected with each of its ends and is suflieiently slack to allow the spring to be drawn out to the desired limit. In some classes of instrun'lents, however, it is desirable that the tension of the spring upon the armature shall never be reduced below a certain point, and for this purpose a knot 0 may be tied in the spring between the guide Y and the rotating post.

In Fig. at the overstraining of the spring is prevented by a wire 0:, formed with hooked ends and lying loosely within the spring. Obviously, when the ends of the spring are drawn against the hook on each end of the wire it cannot further be extended. Of course the details of construction of a stop device for limiting the adjustment of the spring may be varied. The arrangements shown, however, are practical ones, and serve to illustrate the invention.

I am aware that, broadly, devices have been arranged to prevent the ovestraining of spiral springs and do not claim such subj eet-matter, but limit my claim to the specific combinations below recited.

I claim as my invention 1. The combination, with an electromagnet, its vibrating arrnaturedever, the armaturedever spring, and means for gradually adjust IC D 4. The combination of an electro-magnet, its armature-lever, means for adjusting the magnet toward and from the armature-lever, the armature-lever spring, means for gradually adjusting the spring, and a stop for limiting the straining of the spring.

In testimony whereof I have hereunto subscribed my name.

PATRIOK B. DELANY.

lZVitnesses:

EDWD. A. OALAHAN, CHAS. O. ZUKSCHWERDT. 

